Bridge To Terabithia is about Jesse Aarons, a boy who lives on a farm and who dreams of being the fastest runner in sixth grade. When he gets back to school, Leslie Burke, who is a girl, runs faster than him and any other boy. At first, he doesn't like her because she is faster than him, but he eventually becomes her best friend. They build a fort in the forest over the river named Terabithia. When Jesse isn't in town, Leslie decides to go to the fort. When she is swinging over the river, the rope breaks and she drowns. After that, they build a bridge over the river, giving the book its title.

Paterson was inspired to write the book after some of her own experiences. She taught sixth grade, where a lot of the children were like Jesse Aarons. Her son's friend also died after she got struck by lightning, and they were inseparable friends. This represents Leslie, who drowned.

Paterson wrote this book to help her son (and her) get over the grief of Lisa, who was struck by lightning. Paterson has always thought that realistic books are needed more than the stuff that is not needed and happiness that is not realistic.